Area Forecast Discussion
Issued by NWS Tulsa, OK

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FXUS64 KTSA 221136

Area Forecast Discussion
National Weather Service Tulsa OK
636 AM CDT Wed Mar 22 2017

VFR cigs to mostly prevail at all sites through the period.  Exceptions
include brief MVFR cigs early in the period at KTUL and KRVS...and
lowering cigs to MVFR categories late at KMLC and KFSM as
southerly winds being to return. Gusty NE sfc winds across NE OK
and NW AR should lessen as the morning progresses.


.PREV DISCUSSION... /Issued 339 AM CDT Wed Mar 22 2017/

Elevated showers/thunderstorms continue across northwest Arkansas
early this morning. A few of the stronger storms could produce
hail but overall intensity/coverage should continue to trend
downward through the morning hours. Cold front has pushed into far
southeast Oklahoma and will continue a slow progression south
with drier air filtering in from the east.

Low level moisture will begin to lift back north into the area on
Thursday in advance of a strong upper level storm system moving
through the southern Rockies. Models remain in good agreement with
developing band of showers/thunderstorms Friday morning east of
the dry line with convective line sweeping east through the area
during the day Friday. Given the extensive cloud cover expected,
overall instability will remain marginal, however very strong low
level wind fields suggest a damaging wind threat with any of the
stronger bow segments. Locally heavy rainfall will also be
possible, especially across far southeast Oklahoma and northwest
Arkansas Friday afternoon. An additional round of strong to severe
thunderstorms will be possible Friday night in association with
main upper low. Large hail will be the main threat with these
storms given the steep lapse rates and low wet-bulb zero heights
around 7-8 kft.

Brief lull in the weather expected Saturday afternoon/night
before another upper wave approaches from the west on Sunday. In
response, low level moisture will quickly surge back north into
the area Sunday afternoon/evening as a surface low moves out of
the Texas panhandle and tracks near the Red River. Showers/thunderstorms
will spread into the area from the west late Sunday afternoon
into Sunday evening with another round of severe weather possible.
Although deep layer shear will be somewhat marginal (30-35 kts),
low level winds will remain backed ahead of surface low yielding
0-3 km helicity values in the 300-400 (m/s)2 range. Depending on
how far north the true warm front lifts during this time and if
storms can become surface based, an enhanced tornado threat would
be possible, primarily across far southeast Oklahoma.

Active weather pattern continues into next week as additional
storm systems impact the Southern Plains. Highest precipitation
chances appear to be around mid week as another strong upper low
moves out of the Rockies, although there are still some model
differences concerning exact timing.




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